Automatic telephone system



H. H. IDE.

AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED JULY29; 191s.

Patented Apr 18, 1922 4 SHEETS-SHEET l.

272/527 017 fiZflPg/Hjd.

H. H. IDE.

AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED JULY29, 1918- Z 9?. 1T 9%. 8H 4" s Wm w d4 1% m a D1 11,41 3,.QQ7O

H. H. IDE.

AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED JULY'29, 191s.

4 SHEETS-SHEET 3- Patented Apr. 18, 1922.

MON

n. H. IDE.

AUTOMATIC TELEPHONE SYSTEM.

' APPLICATION FILED JULY29, 1918.

1,413,027; Patented Apr. 18, 1922.

4 SHEETS-SHEET 4- To all whom it may concern UNITED STATES PATENT omen nanny Ii. IDE, or LA cannon, ILLmO'Is, AssIeNon 11o xmooe swrrcmaoann AND SUPPLY COMPANY, or CHICAGO, ILLINOIS, A CORPORATION or ILLINOIS.

AUTOMATIC TELEPHONE SYSTEM.

Application filed July 29, 1918. Serial NO. 247,122.

Be it known that I, HARRY H. Inn, a citizen of the United States of-America, residing at La Grange, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Automatic Telephone Systems, of which the following is a specification.

My invention relates to telephone systems, and has to do more particularly with automatic 0r semi-automatic systems in which individual line switches are used for connecting a calling line 'to an idle trunk. I

An object of my invention is to; produce an improved switch and circuit arrangement which embodies'desirable features and advantages, all in a simple, eflicient and economical manner, which is most eflicient 'and economical in its operation, and which has its parts so constructed and combined as to make them readily accessible for adjustment and repairs.

One of the features of my invention is the construction of the switch mechanism in several units which may be readily removed and quickly replaced by other assembled units.

Another feature of my invention is the method of controlling the off-normal switch contacts. I

A still further feature of my invention resides in the method of adjusting the pawl guides, etc.

These and other features will be hereinafter more particularly described in the ensuing specification and in the appended claims.

For a better understanding of my invention, reference may be had to the accompanying drawings in which like reference characters denote like parts, and in which:

Fig. 1 is a plan view of the line switch of-my invention;

Fig.2 is a bottom view of Fig. 1;

Fig. 3 is a right side view of Fig. 1;

Fig. 4 is'a rear elevation of Fig. 1;

Fig. 5 is a top view of Fig. 4;

Fig. 6 is a right side view of Fig. 4;

Fig. 7 is a plan view of the line switch showing it in an off-normal position with parts removed to more clearly show the apparatus;

showing the pawl and ratchet arrangement for advancing the switch wipers and also illustrating one of the positions of the OE normal springs v Fig. 9 is a sectional view along the line 99 of Fig. 8; i

Fig. 10.is a view of the wipers;

Fig. 11 is a sectional view along the line 11--11 of Fig. 4;

Fig. 12 is a sectional view of the main shaft showing its construction;

Fig. 13 is a sectional view showing the method of mounting the magnet coils;

Fig. 14 illustrates diagramma ically an automatic telephone system including the line switch of my invention; and

Fig. 15 is a sectional view along the line 15-15 of Fig. 4.

Referring now more particularly to the structure as illustrated in Figs. 1 to 13, in-

' Specification of Letters Patent. t t d A 13, 19252,

elusive, and Fig. 15, the line switch of my invention comprises a mounting plate 2 to which are secured the operating magnets and movable parts of the line switch. The plate 2 also carries a bank of contacts B, the said bank of contacts B cooperating with a set of wipers W, which wlpers W are Worted upon a shaft S. A motor magnet a combined line and interrupter relay LR, and a cut-ofi relay COR are also supported by the mounting plate 2, as is also certain other apparatus which will bemore fully herein-after described.

To support the bank of contacts B upon the plate 2, posts 3 are provided which are secured to the bottc' n face of the plate in any suitable mannei 'cand the said bank of contacts B, as a whole',' is adjustably secured to the posts 3,as will be presently described.

The bank of contacts B comprises the private bank contacts 4, and two sets of line are arranged in horizontal rows, there being ten sets of contacts, each set of contacts including a vertical and a rotary line contact and a private contact. The vertical and rotary and private contacts are radially disposed and are placed between strips of insulation cloth 7 and 8, the vertical and rotary contacts 5 and 6 having a strip of insulation material 9, such as micarta or other suitable material, placed between the said vertical and rotary contacts to properly space and insulate them. The private contacts 4 are alsoplaced between strips of cloth rows of contacts, containing private, verti cal and rotary contacts 4, 5 and 6, are placed between the clamping plates 11 and 12, and

I I .a strip of insulation 13 is placed between the plates 11 and 12 and the contacts to properly insulate the contacts from the clamping plates 11 and 12. Bolts 14 and nuts 15 form the clamping means for securing the rows of contacts together, as a whole, between the plates 11 and 12 to form the contact bank B.

To secure the bank of contacts B to the supporting posts 3, I provide the lower A clamping plate 12 with ears 12' and 12 preferably formed integral with the said plate 12. The cars 12 and 12 are bent over parallel to the plane of the plate 12 proper.

The ears 12 and 12 of the plate 12, and

the plates 11 and 12 are provided with openings of -a size to receive the posts 3. The

contact bank B, as a whole, is slipped on the posts 3, and when the bank is in a desired position the screws 16, which have screwthreaded engagement with the bridge portion of ears 12' and 12 are tightened to maintain the bank of contact-s B, as a whole, in its adjusted position. Lock nuts 16 are provided, which, when he screws 16 are tightened, lock the screws to prevent-them from loosening and allowing the bank B to shift.

Adapted to co-operate with the private and line bank contacts 4, 5 and 6, are the bank wipers or active contacts 17 18 and 19'. The private wiper 17, vertical wiper 18 and rotary wiper 19 are mounted'upon a shaft 8 and suitably insulated therefrom. A wiper carrying hub 20 is provided for carrying the wipers 17 18 and 19. The said hub is provided with shouldered portions 20', and a pair of disks 21 and 22 are provided with openings 21 and 22 of a size to receive the shouldered portions 20, of the hub 20.

When the'disks 21 and 22 are in position on the hub 20, the shouldered portions 20 lprotrude slightly, and the protruding portion is turned over in any suitable manner by means of staking to securely attach the disks 21 and 22 to the hub 20.

The line wipers 18 and 19, and the private wiper 17, are similarly constructed and the description of oneis suflicient. 4 The private wiper 17 has a ring-shaped body portion 17' and an extending arm .17 in the form of a. wiper with a flared end for contacting purposes with the rivate contacts 4. The said privat wiper -1 is fastened to the disk 22 by means of screws 23, but suitably insulatedfrom the disk 22 and screws 23, the said screws 23 havin screw-threaded engagement with suitab e tapped openings in the disk 22.

The line wipers 18 and 19 are similarlyconstructed and are rovided with extending arms 18 and 19 in t 1e form of wipers, which arms are provided with flared ends for contacting wlt-h the vertical and rotary bank ed engagement with suitable tapped openings in the disk 21 and are suitably insulated from the said Wipers. The hub 20 is provided with a set screw 25' which has screwthreaded engagement with a suitable tapped opening in the hub. The wipers 17, 18 and 19, and hub 20, as a whole, are slipped over the shaft S, the said hub being provided with a central opening 26 for this purpose,

and when the-wipers are adjusted in alignment with the contacts 4, 5 and 6, respectively, the set screw 25 is tightened to hold the wiper unit W in its adjusted position upon the shaft S.

A cylindrical sleeve 27- is provided which is supported by the plate 2 and serves as a bearing for the shaft S. The sleeve 27 also acts as a bearing for the ratchet 28 which operates to rotate the shaft S to rotate the wipers W over the contacts of the bank B. A spring casing or drum 29 is also mounted upon the sleeve bea-rin 27 and carries a spiral spring 30, the said spring 30 having one end fastened to the spring casing 29 and the other end fastened to the sleeve 27.

The tension of the spring 30 is such that it has a tendency to hold the shaft S in its normal position. I

The sleeve 27 has its one end 27 threaded and its other end is provided with afianged portion 27 the said flanged portion resting in a recess in the ratchet 28. A collar 31 is threaded onto the sleeve 27, and its upper peripheral surface forms a bearing for the spring casing 29 which'contains the restoring spring 30. The lower portion of the collar 31 is provided with a reduced portion 32 which fits into a suitable opening 33 in the mounting plate 2. I provide a nut 34 which has screw-threaded engagement with the threaded portion 27' of the sleeve 27, and when a proper adjustment of the ratchet 28 and parts is obtained, the nut 34 is tightened to secure the sleeve and supported parts in their adjusted position. A plate 35 is secure-d to the ratchet by means of screws 36,

37 and 38, the said screws 36 and 37 having in-the ratchet 28 and the reduced ends "36 and 37 enter suitable openings in the spring 1} casin 29 to keep the said spring'casingr29 yand t e ratchet 28 in roper relation. he

screw 38 has screwreaded engagement with a suitable tap ed opening in the ratchet {28- to secure the p ate 35 to the ratchet 28. p The shaft S is provided with'a squared por- 'tion40 at its upper end which enters a square :opening 41 in the plate 35. A screw'42 hav-qtion in the post 44: The plate'35is provide d threaded engagement witha suitable'tappedf opening in the core of themag'net 50s "The. stud 52, through which the screwv 5,1pass'es,

serves as an adjusting means-for the mag- I i when theshaft screw 51 is loosened and the stud withnan upturned portion 35';' :wh-icha;

' adapted to enga e the 'screw stopfit 'solthat is in its normal position the: portigh 35, rests against :the screwgs'top,43 to limit the restoring movement of'sha-ft Sui The motor ma net MM, whichis' adapted 1 to move thesha t S andfwipers 17,18amjl U 19 over the contacts'4, 5 and 6, includes a pole piece .47, an armature 48, and a drivpawl 49.

net in a forward or backward direction a'nd'has screw-threaded engagement with a.

suitable tapped openingin the-heel iron 47,

the other end of the stud 52 being provided;v with an integrally formed hexagonal head To adjust. the electromagnet 50, the 52 turned to the right or left, as the-case may be, to properlyadjustthe magnet Y50, and when this adjustment is obtained a lock nut 54 is tightened to hold the stud 52 in its adjusted position. projecting ears '55 bent at right angles to the main part-of the said pole piece,- the said ears having suitable tapped openingsnet 50 and pole piece 47, as a unit, to the The pole piece 47 has which receive screws 56 to fasten the magmounting plate- 2.,- The polepiece 47 is "provided with projecting ears 68, bent at right angles to the main part of the! ole piece, the said ears having suitable openings to receive a pivot pin 69, which pivot pin pivotally supports the armature'48 of the motor magnet MM; The armature 48 is also provided with ears which have suitable openings to receive the said pivot The electromagnet .50 is suitably secured to the pole, piece 47- ,b' j means of a screw 51 whichpiisses throng a stud 52, the said scre-w- 51- havingscrew- '69 is inserted through the openings .inthe earsf68fjof the pole piece; '47 v and, ears of the; armature 48, "and 1 through the openings in the arms of the-U-sh'aped mam-- ber'71. ,One arm of the member71 fits between one Ofthje supporting ears 68 of the "pole piece 47 and the-adjacent rear 70 ot' the armature 48,; A. set screw72 is provided and has 'screw-threaded engagement with the ,"yoke endof'- the, U-shapedmember 71 and I when the screw 72' is; tightened lit engages-the ear e1, -drawin -wpinf69fa ainst -,,the opening in the ears"7O -and ,6 8, an this holds thepin 69 in positionz fThe,set screw 72 is-used to securelyfllilold the pivot in 69 i t Place relative fto t efheel' ron 4 iand H v 1"?8,parriesa -pivoted pawl which; is normallyj held against an adus table. stop 58 by means-Of a. leaf spring 59,- the said leaf spring' lbei'n held in place by means of a screw 59;";- he' adjustable stop 58 is pivotally secured t ofthe mounting 'plate'2 by means offal: screw 6O. The stop 158 has an enlarged end 58"provided with I a slot 61, through which thescrew 62 passes. "To-adjust the pawl ,49, the screws 60 and '62, 'arejloosened fandthe stop 58 is then moved about the pivoted screw 60', causing the upturned portion "58 to move to theright or left, as the casemay be, and when the proper adjustment'is obtained the screws 60v and 62, which have screw-threaded engagement with suitable :tapped openings in he plate 2, are tightened-to holdit in its adjusted-position. j. The armature 48 is held in its normal position lb means of a coiled spring- 63, the said'coilbd spring 613 having its. one end fastened to a pin 64 which is staked to the pole piece 47, and the otheri end of the spring 63tis secured to anadjustablescrew 65. The screw 65 passes through a suitable opening in the arm 66, which arm is integrally formed with the-mature 48,'the said screw being provided with an adjustable nut 67. The tension of the sprin 63' is regulated by means of the nut 67. A set of contact springs J are associated with the motor magnet MM, the saidsprings being insulatingly 77 which operates the springs of the set J upon the attraction of, armature 48 when the magnet MM is energized. An adjustable screw stop 78 is provided, which screw has screw-threaded engagement with the ole iece-47 and acts as a stop for the arm 6 w en'the said arm 'is in its normal 0- sition. An adjustment screw 79 is provi ed and has screw-threaded engagement with the pole piece47, and is used for adjusting the normal position of springs 80 and 81. A- leaf spring 82 is provided and is mounted upon the pole piece 47 by means of the screws 73. A rubber buifer 83 is carried by spring 81 and is used to prevent the said spring 81 from contacting with spring 80. The springs 80 and 81 may be adjusted so that they are separated upon a partial attraction of the armature 48, or

not until a full attraction of the armature 48 takes place. This adjustment. of-"the springs 80and 81 of. relay MM is for the purposeof timing the .instantat which the line relay LR has its circuit interrupted, as will be more fully herein-after described.

The pawl '49 is adapted to engage a. tooth of the ratchet 28 u on each actuation of the motofmagnet M, and an adjustable post 120is provided to limitthe stroke of the pawl 49 so that the wipers 17, 18 and 19 are only advanced one step at a time The post 120,, has a threaded stud 120 which.

passes through a suitable slot 121 in the plate 2. The stop' 120 may be'moved for ward or backward 'as-the case may be, and when the desired adjustment is obtained a nut 122 having screw-threaded engagement hold the sto in its ad usted osition.

The cut-o relay C R- inc udes a pole piece 85, electromagnet 86, and an armature 87. The magnet 86 is adjustably mounted to the pole piece 85 in a manner similar to that previously described in connection with the motor magnet MM. The electromagnet 86 and pole piece 85, as a unit, are fastened otally supports the armature 87 in a mannersimilar to that previously described in conwhen the armature, .87 isin-p'osition and'pin 90 inserted, and the set screw v93 t1ghtened,

the armature 87 ispo'sitioned as reviously' described in connection with relay 3 The armature 87 is held in its normal-peasant means of a coiled spring;94, thesaid coile andits other end is secured to a screw 96. The screw passes through a suitable open ng in the arm 97,'which arm is formed mtegrally with the armature 87 ,the said screw provided and suitably mounted. upon the face of the armature 87 by means of screws 101, the said plate being provided with an -80 vangularly extending arm 102 preferably f formed integrally with the plate 100. The arm 102 is provided with a rubber buffer 103 which operates the springs of set L upon the attraction of armature 87 when the relay .85

COR is energized. An adjustable screw stop 104 is provided, which screw has screwthreaded engagement with the pole piece 85, the said stop 104 acting as a stop for the arm 102 when the arm is in its normalposition. I i 90 provide a set of off-normal contacts-ON which are moved to their alternate position upon the first movement of the switch shaft S off normal. An angular mounting plate I 105 is provided,being suitably fastened to 95 the main mountingplate 2, upon which the off-normal contacts 106, 107, 108, 109, 110, 111, 154 and 155 are insulatingly mounted by means of screws 112. An angular extension I i v 35 0f the plate 35, when the shaft S and with the stud 120' 1s tightened to securely,

wipersW are in theirnormalposition, en-

' gages an arm 113 pivotally supported on the plate 105' by means ofa pivot pin 114 to hold the springs in their normal position. The arm 113 is supported betweenears 115 105 formed integrally with the plate 105, the pivot pin 114 passing through suitable openings in theears 115 and 116 on arm 113 to support the arm 113 in position. A buffer 117 carried by the arm-1l3 engages the springs to hold them in their normal positions. Upon the first step of the wiper ofi' normal, the extension 35 disengages the am 113, allowing the springs ON to assume an alternate position, as most clearly illustrated in Fig. 81- Some. of the said springs are;

moved to. another alternate position upon attraction of the relay COR, as will be hereinafter morefully explained. The off-normal contacts ON. are again restored to nor 1 -mal upon the; restoration of the shaft 8 by 112]" nection w th the motor magnet MMso that:

the spring 30,- due to the angular extension j-{f 3 5?again engagingthe'arm 113, moving itfi to the left to force th'e'oif-normal contacts";-

ON intdtheirhormsil position.

Toj'jh'old theiwipers in their advanced poi- 1on,'=I provide a-retaining pawl 123, pivotany .securedfto the {plate 2 by-means of the pivOtscrewq124; Thewretaining pawl 123 an arm 125, preferably 1 causing the pin 138 to'leave the angular porformed integrally therewith, and a 'leaf spring 126 has its one end suitably fastened to a bracket 127, which is preferably formed integrally with the plate 105, by means of a screw 128. The free end of the spring 126 engages the arm 125 of the pawl 123 to force the nose 123' of the pawl 123 into en agement with a notch in the ratchet 28. ssociated with the retaining pawl 123 is a pivoted bar 129 pivotally-secured to the plate 2 by means of the pivot screw 124, which screw also pivotally secures the pawl 123, as before mentioned. A link 130, associated with the relay COR for purposes as will presently be described, has its one end pivotally secured to the armature 87 by means of a pivot pin 131, and its other end is provided with a suitableslot 133, through which 'a screw 134 passes, the said screw 134 having screwthreaded engagement with .a suitable tapped opening in one end of the bar 129 to slidably connect the said link 130 with the bar 129.

A pawl 135, pivotally secured to the mounting plate 2 by means of the pivot screw 136, is normally held out of engagement with the ratchet 28. The pawl 135 is provided with an angular extension 137 and has a pin 138 secured thereto in any suitable manner, as by staking. A slot 139 having an angular portion 139 is cut in the link 130, and normally the pin 138 of pawl 135 rests in the portion 139' of the slot, thus holding the pawl 135 out of engagement with the ratchet.

The bar 129 has an angularly-shaped extension 1'50, which extension is provided with a pair of notches 151 and 152. These notchesco-operate with a downwardly BX" tending arm 153 of arm 113 so that upon the first step of the shaft S off normal, the extension 35 disengages arm 1 13, allowing the said arm 113 to move to the right, allowing arm 153 to engage notch 151 of the extension 150 of bar 129, and also allowing olf-normal contacts to assume an alternate position. Upon the energization of the cut-off relay COR, the link 130, being pivoted to the armature 87, is moved backward tion 139 of the slot 139 and enter the vertical portion 139 of the slot 139. This causes link 130. causing the bar 129 tobe movedabout its pivot screw 124. The angular extension 150 engages the arm 125 of the pawl 123, causing it to rotate about its pivot screw 124, causing its nose to disengage the tooth of'the ratchet'28. The pawl 135 engages a tooth of. the ratchet 28 before the pawl 123 disengages atooth of the ratchet 28 to prevent a premature release of the switch. The bar 129 being pivoted by the pivot screw 124, the end provided with the extension 150 moves forward causing the and springs 110 and 155,- as is most clearly illustrated in Fig. 7 and as will be more fully hereinafter described. Upon the release of the switch, the cut-off relay COR de-energizes, allowing the armature 87 to retract, drawing the link 130 forward,-and the pin 138 again entering the angular portion 139 of the slot 139 causes the pawl to rotate about its pivot screw 136 to withdraw its nose from engagement with a tooth of the ratchet 28. The shaft S being free to restore, the spring 30,restores the shaft S and wipers W to normal, and when the extension 35 again engages the arm 113 it moves it to the left and 'causes-the extension circuit changes between the pawl 123 to their normal positions, the said pawl 123 again engaging atooth of the ratchet 28 and the extension 15.0 again. resting against the extension 153. The arm j 113 in moving to the left restores off-normal contacts ON to their normal positions.

suitably fastened to the condenser K and'a screw 141 which passes through a suitable opening in the bracket 140.- The 'said screw A condenser K is mounted upon the. mounting plate 2by means of a bracket 140 141 having screw-threaded engagement with a suitable tapped opening in the plate 2, secures the condenser K to the mounting plate 2. A line relay LR: issuitably' supported by a bracket 142, which bracket is in turn secured to the plate 2 by means of a screw. 143. The line relay LR is secured to the bracket 142 by means of the nut 144, which nut. has screw-threaded engagement.

with the threaded extension. of the core of,

.the relay LR. The line relay LR comprises a heel iron 145, electromagnet 146, armature i 147, and a pair of interrupter spring con-1 tacts 148'and 149, for presently described.

purposes as jbe' I represent diagrammatically- Fig.1 i

a complete circuit arrangement; necessary for connecting 'a callin called subscriber. The circuit shows a calling substation A terminating in an individ ual line switch B. The-line switch B il1us-.

subscriber ;to a] trates the circuit arrangement of the switch of my invention, and is adapted to selectan idle connector C, the connector in turn being the called substation D. The called subsubstation A ineludes'the usual talking apadapted to connect to the terminals of g circuit for the line relay LR is established,

'paratus ofa common battery telephone and,

Serial No. 175,364, filed June 18, 1917.

Assuming now that a call is to be traced from the calling substation Ate the called substation D, upon the removal of the receiver by the subscriber at the callin substation A, a circuit for the line relay R of the individual line switch B. is established, traced from battery through the winding of the relay LR, normal contacts 80 and 81 of the motor magnet MM, conductor 200, normal contacts 155, 110 and 109, conductor 201, I normal contact 202 of relay COR, through- I the closed contacts of the substation switch hook, back through normal'contact203 of. relay COR and conductor204, to groundat normal contact 154 through contacts 106 and 107'. The relay LR, upon energization,

' closes its contacts 148 and 149, closing an energizing circuit for the motor ma et MM, traced from battery through the muding of the magnet MM, through the now .closed contacts .148 and 149 of relay LR to ground. The motormagnet MM attracts its armature 48, causing the pawl 49 to engage a tooth of the ratchet 28 and step the shaft S and wipers 17 18 and 19 into engagement with the first set of contacts 4, 5 and '6. Upon the first step of the wipers ofi' normal, the extension 35 of plate 35 disengages arm 113 and allows off-normal contacts ON to assume an alternate position; that is, contacts'1061and- 107 are open, and contacts 107 and 108 are closed; contacts 109 and 110 are opened and contacts 110 and 111 are closed. Contacts 154 and 107 remain closed as do contacts 155 and 110 upon this movement-of the cit-normal contacts, Upon the energization of magnet MM, its contacts 80 and 81 are opened, opening the energizing circuit of the line relay LR, and the line relay LR. restoring opens its contacts 148 and 149, opening the energizing circuit of the magnet MM. If the firstset of contacts 4, 5 and 6 is, idle, that is, if there is no ground on the private contact 4, the switch remains on the first set of contacts engagedQ Should the first set be busy, there will be a ground upon the private contact 4, and another energizin traced from battery through-the winding of. the relay LR, contacts 80 and 81, conductor 200, contacts 155, 110 and 11 1, conductor 205,

opened and closed upon each ener ization nd de-energization of ma et M and $1611 eachclosur'e of norma contact 208 a circuit is closed throu h winding 209 of. relay COR, traced from atter throu h the lower winding 209 ofrela C611, conductor 210, conductor 211, norma' -contact 208, con-' ductor 212, alternate contact 108-and contact 107, to ground at contact 154. The winding 209 of relay COR isof hi h impedance, an as the motor'magnet M ener izes and. deenergizes with great rapidity, t c said winding 209 does not energize during the time that the-motor -magnet is operating. The ground at contact 154 is connected to the private normal contacts 214 of the connectors having access to the calling line to render the contacts-busy, the ground extendin over a circuit traced from contacts 154 an 107, through closed contact 108, over conductor 213 to said connector bank contacts 214. When an idle private contact 4'is encountered, relay LR and magnet MM remain at normahand the closing of normal contact 208 of relay MM now establishes an ener- The relay COR, upon energizing, closes its make-before-break contact 215, closing a circuit throu h the upper winding 216 of said relay f COR, traced from battery through winding 216, make-before-break contact 215, conductor 211, contact 208, conductor 212, to ground at contact-154. 1 This circuit through this winding gives the relay COR a positive energization, and the link moves backlit ward, due to the attraction 10f armature 87 rocking the bar 129 to bring about the withdrawal of pawl 123 from the ratchet 28, and moving causes the pawl to move into engagement with the ratchet 28. The .move- J29 ment of the bar 129 causes the extension 153 of arm 113 to leave notch 151 and enter notch 152 in the extension of bar 129. This movement-permits contacts 107and 110 of off-normal springs to. move to their 12s final position, thereby causing contacts 154 and 155 to break connection with contacts opening of contacts 154 with contact 107 opens the initial energizing circuit of relay COR, but the relay CO bemg slow to release is held up momentarily until a substitute circuit is established for the said relay COR, as will presently be described. The opening of contact 155 and contact 110 disconnects the line relay LR and motor magnet MM to prevent any further stepping of the switch. The circuit which is momentarily closed through the upper winding of relay COR is opened upon the full attraction of the armature of said relay COR.

The relay COR having been energized, its contacts 202 and 203 assume their alternate position, and as the wipers 17, 18 and 19 have engaged contacts 4, 5 and 6, leading to an idle connector, a circuit for impulse relay IR of connector C is established, traced from -20 battery throu h the left-hand winding of relay IR, con 'uctor 217, contact 5, wiper 18, alternate contact 203 of relay COR, through the substation A, back through alternate contact 202 of relay COR, wiper 19, contact 6, conductor 218, and through the right-hand winding of relay IR'to ground. The closing of alternate contact 219 of relay IR closes the substitute circuit for the relay COR of line circuitB, traced from battery 80 through the lower winding 209 of relay COR, conductors 210 and 211,,normal contact 208 of relay MM, conductor 212, alternate contact 206 of relay COR, conductor 207, wiperj17, contact 4, conductors 220, 221

36 and222, to"ground at alternate contact 219 v ofrelay IR.

v The energization of the relay IR brings about the energization of the relays 223 and 224, the circuit of relay 223 extending from 40 battery through the right-hand winding of said relay, normal contact 225 of the primary off-normal contact PON, conductor 220 and conductor 221 to ground at alternate contact 219 of relay IR. The circuit for relay 224 extends from battery through the lower winding of the relay 224, conductor 226, conductor 227, and alternate contact 228 of re lay IR to ground at alternate contact 219 of impulse relay IR. Upon the energization of relay 223, a lockingcircuit is closed for the said relay, extending from battery through its alternate contact 229 to ground.

Assuming that the called subscribers num-.. ber at-substation D is 45, the subscriber now operates his calling device CD to send four These de-energize four times to step the wipers 230,

231 and 232 in a downward primary direction to the fourth group. ofcontacts containing the contacts'of the called line. The circuit of the primary magnet-PM may be traced from battery through the winding of the said magnet, normal contact 233 of switching relay SW, conductor 234, alternate contact 235 of relay 224, normal contact 228 of relay IR, conductor 221, conductor 220, and normal contact 225 of the primary off-normal contacts PON to ground at alternate contact 229 of relay 223.

After the primary off-normal contact 225 has moved on the first step of the switch shaft, the ground fed from contact 236 of relay 237 is substituted for the ground fed through contact 229 of relay 223. After the last impulse of the series has been sent, the steady flow of current through both windings of relay 224 causes the said relay 224, due to its difi'erential action, to neutralize and restore its contacts to normal. Relay 224 does not restore during the sending of impulses due to its adjustment, construction, and the rapidity of the interruptions of contact 228. The closing of normal contact 238 of rela 224 brings about the energization of the switching relay SW traced from battery through the winding of said relay to makebefore-break contact 239 of said relay, normal contact 240 of secondary off-normal springs SON, conductor 241, normal contact 238 of relay 224, and conductor 242 to ground at alternate contact 243 of primary off-normal contacts PON, the said primary off-normal contacts PON having been moved to their alternate position. on the first step of the wipers 230, 231 and 235 of the connector switch. The closing of alternate con tact 233 of the switching relay SW now renders the secondary magnet SM operative so that when the calling subscriber at the substation A actuate's his call device again to send the last set of impulses, which we have assumed are five in number, the said magnet SM will be energized and de-energized by the impulse relay IR five times over a circuit traced from battery through the winding of the said ma net SM, alternate-contact 233 of relay S conductor 234,valt ernate contact 235 of relay 224, normal contact 228 of relay IR, conductor-I 221, conductor 220, and alternate contact225fof the primary off-normal contacts'PON, and conductor 244 to ground at normal contact 236 of relay 237. The secondary magnet SM now steps the wipers 230, 231 and 232 in a secondary rotary direction to engage contacts 245, 246 a-nd247. of the called Iline; Upon the first impulse of the last set', the relay 224 again energizes to, permit. the secondary magnet SM 'to be operated, and after the last impulse the relay 224 is again de-energized, as previously described. The restoration of the relay 224 closes a circuit for the test relay TR traced from battery through the winding of the said relay, conductor 248, the alternate contact 249 of relay SW,'altern'ate'contact 240 of the secondary oif-normalcon tacts SON, (said contacts having been said relay over conductor 251 to the test.

wiper 230, and should the called line be busy the private contact 245 of the called line would be grounded, thus closing a locking circuit for the said relay TR through the private wiper. I

Called Zine idle.

Assuming that the called line is idle, private contact 245 of the called line will have a battery potential upon it, and the relay TR will not remain energized but will deenergize. The openingof normal contact 252 of relgiy TR 0 ens the circuit of the switching relay S The relay SW do energizing, opens the circuit for relay TR at its contact 249, leaving the relay TR dependent upon the potential found upon the private contact 245 of the called line for its holding potential; and, as assumed, this contact is free from ground potential, therefore the relay TR tie-energizes and returns to normal. The relay TR de-energizing causes the energization of the relay 23mm a circuit which may be traced from battery through the cut-off relay COR, to bank contact 245, through wiper 230, conductor 251, normal contact 250 of relay TR,- conductor 253, normal contact 254 of relay SW, conductor 255, through the lower win ing of the relay 237, and conductor 256 to ground at alternate contact 257 of relay 223. The closing of alternate contact 258 of relay 237 short-circuits the lower winding of the said relay, and the closing of alternate contact 259 of relay 237 closes a circuit through the upper winding of the said relay, through the alternate contact 259 and conductor 256 to ground at alternate contact 257 of relay 223. i

The closing of alternate contact 260, of relay 237 connects the interrupter I to the relay 261.

contact 265 of ringing control-A relay RC,

conductor 266, alternate contact 267 of relay 237, conductor 268, normal contact 269 of relay261, wiper 232, bank contact 247,

The circuit for relay 261 may be traced from battery through the winding through the condenser and call bell of the called substation, backthrough bank contact 246, wiper 231, normal contact 270 of relay 261, and conductor 271 to ground at alternate contact 236 oi relay 237.

The call bell of the. called subscriber at the substation D is thus intermittentlyrung, due to the energization and de-energization of the relay 261 by the interrupter I. When the called subscriber answers and the relay 261 is in its energized position, a circuit for the relay SR is closed, which may be traced from battery through the lower winding of the relay SR, through alternate contact 259 of relay 261, wiper 232, contact 247, through the now closed contacts of the substation switch hook at the called substation D, back through contact 246,

wiper 231, alternate contact 270' of relay 261, and through the upper winding of. the.

the said relay and make-before-break contact 272 to ground at alternate contact 273 of relay SR. The closing of alternate contact 274 of relay RiC closes a locking circuit for the said relay which may be traced from battery through the-Winding oft-he said relay, its alternate contact 274 and conducductor 242 to ground at alternate contact 243 of the primary ofi-normal contacts PON. The openingof normal contacts 264 and 265 disconnects the interrupter I and theringing generator RG to prevent further application of ringing current. A substitute circuit for the relay 261 is now estabhshed which may be traced from battery through the winding of the relay 261, conductor 262, alternate contact 260 of relay 237, conductor 263, alternate contact 264 of relayRC, and conductor 242 to ground at I alternate contact 243 to primary ofi-normal contacts PON. The subscribersare now in conversational circuit, and the talking circuit may be traced'over the heavily marked conductors, said conductors having the condensers K and K interposed.

The subscribers having finished conversation, and assuming that the subscriber at the calling substation A is first to replace his receiver upon the switch hook, the opening v IR of the connector C. The restoration 0 the reof the switch hook contacts brings about the deenergization of the impulse relay lay IR brings about the opening of the holding circuit of the relay COR of the individual switch B, which relay COR restores, and the armature of relay COR moves the link forward, causing the pawl to disengage a tooth of the ratchet 28 due to the pin 137 entering the angular por-v tion, 139- of the slot. The spring 30 .now

restores the wipers to normal, and when the extension 35 engages the arm 113 it restores the off-normal contacts ON-to normal and PON, through t the spring 126 turns the bar 129 and pawl .123 about the pivot screw 124, allowing the V scriber D fail to replace his receiver upon the switch hook after the conversation is bar to assume its. normal position, and allowing the pawl; 123 to again engage a tooth of the ratchet;

The subscriber D restoring his receiver.

u on its switch hook interru ts the circuit 0 the-relay SR at the switch ook contacts,

causing the said relay to de-energiz'e. The

closing of normal contact 280 of relay SR closesa circuit through the left-hand winding of the relay 223, which maybe traced from battery through the left-hand winding of the said relay 223, alternate'contact 281 of relay 223, conductor 282, no'rmal contact 280 of relay SR and-conductor 283 to round at normal contact 219 of relay IR. no to the differential construction of relay .223, the said rela neutralizes and restores to normal. The closlng of normal contact 284 of relay 223 closes an ener izin secondary magnet SM, conductor 285, normal contact 284 of relay 223, alternate contact 286 of the rimary-ofi normal contacts lie interru The secondary magnet S thus steps, the wipers 230, 231 and 232 be ond the last'set of contacts in the group.- l

spring tension. The restoration of the relay 223 brings about the opening of the circuit of the relay 237 at alternate contact 257, and the relay 237 restoring opens the circuit of relay 261 at contact 260 of rela 237, and the primary off-normal contacts P N having restored upon the restoration of the SWltCh the opening of the alternate contact 243 o PON brings about the de-energization of the relay RC. The relay 223 also brings about the de-energization of the cut-off relay COR of the line switch B which is associated with the called subscriber D. All the apparatus used in establishing a connection between a calling subscriber at the substation A and the called subscriber at the substation D is now atnormal and available for use in establishing other connections. Assuming now that the subscriber at the called substation D was first toreplace his receiver upon the switch hook, theopening of the switch hook contacts at the substation 1) brings about the de-energization of'the relay SR. Nothing else happens at this-time as the relay IR "is still maintained energized over the line of the calling substation The calling subscriber at the substation A replacing his receiver interrupts the circuit of the impulse relay IR- at the switch hook contacts. The relay IR de-ene' qgizing closes a circuit for the left-hand winding of relay 223, causing'the said relay to de-enercircuit for the sec .ondary magnet Si w ich may be traced from battery through the winding of. saidter '1" to ground; 7

he wipers then. 7 restore to normal from this position" by 'gize, as herein-beforev described. The restorationof the individual switch B and connector C- is the same as previously described from this point on. Should the called subterminated, the replacing of the receiver at the substation A brings about the de-energi zation of the impulse relay- IR of connector C, the same as before, and the opening of alternate contact 219 of impulse relay- IR opens the circuit of'the relay COR of,.indivldual switch.B'as before described -and causes the release of switch B, a

The subscriber at the" called substation failing to replace his receiver, permits the v continued energization of the relay SR, thus holding the contact'280 of said relay in its alternate position, preventing the difieren tial woundrelay 223 from restoring to normal and closing the ener izing circuit for the secondary magnet S energizes when the line relay IRdrops back but is immediately restored to normal due to the closure of an energizing circuit through the lower winding of the said relay 224,

The relay 224 which may be traced from battery through the said lowerwinding, conductor 226, aiternate contact 280, connector 271, to ground at normal contact 219 of the now restored. impulse relay IR. .Relay 224- being difi'erentially wound, restores to normal, and the closing of normal contact 290 of the said relay 224 places a ground upon the private contact of the connector (J over a circuit which mav be traced from ground at alternate contact 243, of the primary off-normal contact PON, conductor 242, normal contact 238 of relay 224, conductor '241, alternate contact 240, normal contact 290, alternate contact'291 of the secondary off-normal con-'- tacts SON, to the private contact 4. The placing of this busy potential upon the private contact prevents any individual switch B from engaging the contacts of this busy connector. 1

' Called Zine busy.

Assuming now that the called line is busy, the operation of the circuit is the same up to and including the time that the relay TR its alternate contact 250, conductor 251, and 1 the wiper 230 to ground at contact 245. The closing of alternate contact 292 of the test relay TR connects the busy signal BB to the line to transmit a busy signal to said calling subscriber at substation A, thus notifying him of the busy condition of the said'called substation I). The relay TR upon locking up to ground at the private contact 245,

make-before-break contact 272, normal contact 273 of relay SR, normal contact 249 of relay SW, conductor 248, alternate contact 250 of relay TR, and conductor 251 to the rounded priv'ate contact. 245. The relay ItC thus closes a locking circuit for itself,

' traced through the winding of saidrelay RC, alternate contact 274, conductor 242 to ground at. alternate contact 243 of the oil'- normal contacts PON. Now should the line called become idle during the time the busy signal is being transmitted to the calling substation, the falling back of relay TR will not cause the called subscriber to be signaled owing t the-Iact that relay RC is locked up to ground at contact 243. The calling subscriber now replaces his receiver, bringing about the de-energization of the impulse relay IR. The relay IR restoring, opens the circuit of the relay COR of the individual switch B to release the switch, as previously described, thus bringing about the release of the individual switch B. The relay IR deenergizing, brings about the restoration of the relay 223, due' to the fact that the relay SR has not been energized. The closing of the circuit through the left-hand winding of the circuit 223 brings about the neutralization of said relay 223. The closing of normal contact 284 of the said relay 223 closes a circuit through the secondary magnet SM, which magnet steps the wipers 230, 231 and 233 beyond the last set of contacts. The wipers then restoreto normal by spring tension. The primary ofl-normal contacts FUN and secondary oif-normal contacts SON are also restored, and the apparatus used in this busy connection is now at normal and available for use in establishing other connections.

While I have shown a system of 100 capacity, it is to be understood that by insert-,

ing first selectors the system may be increased to a 1,000 system, etc. It is to be understood that I do not wish i to be limited to the exact matter shown. as

ing magnet including a contact of said test,

magnet.

2. A telephone system including a. non- 1. numerical automatic svfitch provided with wipers'and only three operating ma ets, a motormagnet for advancing said wipers, a test magnet, and circuits for said motor magnet and said. test magnet controlled by contacts of each other whereby when one of said magnets, energized it operates to deenergize the other of said magnets.

3. A telephone system including a nonnumerical automatic switch provided with wipers and only three operating magnets, a

motor magnet for advancing said wipers, a I

test magnet,"and circuits for said motor magnet and said test magnet" controlled by contacts of each other, whereby when one of said magnets energizes it operates to demagnet for said switch, a circuit for said motor magnet including contacts of said test magnet, and a circuit for said test magnet including contacts of said motor magnet and said cut-oil magnet.

5. A telephone system including an automatic spring restored trunking switch having motion in one plane only, shaft-operated contacts for said switch, a test magnet, a

motor magnet and a cut-off magnet for said switch, and a circuit for said test magnet includkilng contacts of said motor magnet, said s aft-operated contacts, and a contact of said cut-ofi' magnet.

6. A telephone system including a sub- 'scribers telephone line, a link circuit, an automatic switch for connecting said link circuit and said subscribers line, a test magnet for said switch, a circuit forsaid test magnet including said subscribers line, a second circuit for said test magnet including a passive bank contact of said switch, said latter circuit being opened upon each step of said automatic switch and arelay adapted to be energized whenthe idle link circuit is found to connect a busy line to the link circuit.

7. A telephone system including a subscribers telephone line, an individual trunking switch for said line, trunks adapted to be selected by said switch, a test magnet and a motor magnet for said switch, a circuit for said test magnet including said subscribers line, a second circuit for said test magnet including conductors of said trunks, said latter circuit adapted to be opened upon each energization of said motor magnet, and a relay adapted to be energized when an idle trunk is selected to connect the subscribers line to the trunk.

8. An automatic non-numerical trunking switch including a motor magnet, a threeposition circuit controlling switch for said 80 energize the other of said magnets, and a automatic -switch, an auxiliary magnet, means controlled by an operation of saidmo-I tor magnet for movin to its. intermediate osltion, and means cn-' for releasing said holding pawl.

said switch contact trolled by said auxi iary magnet for moving said switch contact to its third position. 9. An automatic non-numerical trunking switch including a motor magnet, a thl68- position circuit controlling switch'for said automatic switch, an auxiliary ma et,

means controlled by an operation of sai motor magnet for moving said switch contact to its intermediate position, meanscontrolled by said auxiliary magnet for movingsaid switch contact to its third position, and a spring restored switch shaft for returning said switch contact to its normal position.

10. A device of the character described ineluding-a pair of normally closed switch contacts,'.a thlrd contact, a magnet for moving said pair of contacts .into engagement with said third contact, and means for then separatingone of said pair of contacts from the other of said pair-of contacts.

11. An automatic switch including a pair of normally closed switch contacts, a third contact, means for operating said contact so that all said contactsare placed in electrical engagement, and means foroperating said contacts so that one of said pair of contacts is separated from the other of said contacts.

12. An automatic spring restored switch provided with a switch shaft and ratchet, a pair of holding pawls for en agement with said switch ratchet, one of-sai pawls adapted to maintain said switch shaft in its advanced position while said shaft is being r0- tated, and means for moving. the other of said pawls into engagement with said ratchet and for moving said first pawl out of en gagement with said ratchet.

.13. An automatic switching device of the ing operation of said switch for moving the other of said pawls into engagement with said switch ratchet and for removing said. first pawl out'of engagement with said switch ratchet.

14. An automatic swltch provided with a shaft and ratchet, a vholding pawl for said shaft, a magnet for removing said holding pawl from engagement withsaid ratchet, means for locking said holding pawl in its disengaged position, and means for unlock ing said holding pawl.

15. An' automatic swltch provided with a I shaft and ratchet, a holding pawl for said shaft, a magnet for removing'said holding for said operating ma switch shaft, an anguarly pivoted guide for v sa1d driving pawl, a 'slotcut in said guide,'

pawl from engagementwith said ratchet,

means forlockin'g said holding pawl in its disengaged position, and means -controlled by the return-of said switch shaft to normal 16; An automatic switc including a-switch shaft, a-magnetprovided with an armature and a pawl for actuating said switch shaft, agulde for said pawl including a pivoted member adaptedto be turned about 1ts piv oted pointto adjust said pawl, and a slot cut in sa1d guide through which a screw extends for securingthe guide in its adjusted posi- 'tipn. 17 An automatic switch including a switch shaft, an operating magnet, a driving pawl et for actuating said shaft and. wipers, interrupter springs for said magnet, micrometric means for adjust ing the normal position of said springs,-and micrometric means for limiting thereturn movement of the armature of sa d magnet.

19. An automaticswitching device of-the character described provided-with a progressively movable switch shaft and wipers, an interrupter magnet for effecting the op-:

eration of said swit'ch shaft and wipers, a

pair of contacts adapted to be'interrupted by said magnet, micrometric means for adjusting the normal position of said contacts,- and micrometric means for adjusting the normal position of the armature of said magnet.

j 20. An automatic switching device'in'cluding a magnet provided with a heel iron, an armature secured to said heel'iron, a flexible spring secured to said heel iron, a pair of interrupter contacts, a buffer resting against said flexible spring for maintaining saidinterrupter contacts in their normal position,

"and micrometric means for moving said flexible spring to thereby adjust said inter-. rupter contacts. I 21. An automatic switchingdevice including a magnet provided with a heeliron, an armature secured to said heel iron, a flexible spring secured to said heel iron, a pair of interrupter contacts, a buffer resting against a said flexible. spring for maintaining said interrupter contacts in their normal position, and micrometric means for moving said fiexible'spring to thereby adjust the relation of said armature and said interrupter contact.

22. A non-numerical automatic switch including a rotatable shaft, a removable drivadapted to beremoved and replaced by other units w'i bout the necessity of disassembling 9r eassembling the parts of the units.

23. An automatic switch including a rotary shaft, a pair of holding. pawls for said shaft, a magnet, and means controlled b said magnet for moving one of said hol ing pawls out of engagement with the said shaft, and for moving the other of said holding pawls into engagement with said shaft. I 4

24. An automatic switch including a rotary shaft, a pair of holding pawls for said shaft, a magnet, means controlled by said magnet for-moving one of said holdintg pawls out of engagement with the said sha t and for movingthe other of said holding pawls into engagement with said shaft means for locking said first holding pawl out of engagement with said shaft, and means controlled by the return of said switch shaft to normal to release said first holding pawl. y 25. A telephone system includin a nonnumerical automatic switch provi ed with an active test contact, a set of passive contacts, a motor magnet, a test magnet, means controlled by said motor magnet for moving said active contact over said passive contacts, means controlled by said motor for connecting said test magnet through-said active contact to each passive contact moved over by said active contact, and means controlled by said test magnet to cause said motor magnet to continue to operate as long as busy passive contacts are engaged by said active contact.

26. An automatic switch including a mounting frame, contact banks supported thereby, wipers for co-operation w1th said contact bank, a shaft for carrying said wipers, a ratchet secured to said shaft, an electromagnet provided with an armature having a driving pawl for engagin said ratchet, and a pair of holding paw s controlled by a single electromagnet for holding the wipers in an advanced position and for releasing the same from such advanced position.

27. A telephone system including a nonnumerical automatic switch provided with only three relays and magnets, a test relay, a cut-ofl' relay and a driv ng magnet, a cir-. cuit for said test relay including a normally closed contact of said driving magnet, and a circuit for said driving magnet including a normally closed contact of said test re ay.

28. A telephone system including a nonnumerical automatic switch provided with wipers, a test magnet, circuits for said motor magnet and saidtest magnet controlled by contacts of each other whereby when either of said, magnets is energized it operates. to de-energize the other of said magnets, a cut-off rela and a circuit forsaid cut-ofi relay inclu ing a contact of said test relay.

29. A. telephone system including a nonnumerical automatic switch provided with wipers, a motor magnet for advancing said wipers, a test magnet, and circuits for said motor magnet and said test magnet controlled by contacts of each other whereby when one of said magnets energizes it opera;

ates to de-energize the other of said magnets, and a magnet for controlling the return of said wipers to normal, said last magnet also controlling the circuit of said test magnet.

30. A telephone system including a spring restored automatic switch, a test magnet, a motor magnet and a cut-off magnet for said switch, a circuit for said motor magnet including contacts of said test magnet, and a circuit for said test magnet including contacts of said motor magnet and said cut-off magnet, said last circuit adapted to be opened when either said cut-off magnet or said test magnet is energized.

31. An automatic individual trunking switch including a motor magnet and a test magnet, circuits for said magnets whereb when either of said magnets is energized it causes the other one to de-energize, and a cut-off relay adapted to be energized by said test magnet when said test magnet remains in its normal position for a predetermined period of time.

32. An automatic individual trunking switch including a motor magnet and a test magnet, and circuits for said magnets whereby when either of said magnets is energized it causes the other one to deenergize, when the last mentioned magnet de-energizes it causes the other magnet to energize, a cut-off relay, and a circuit for said cut-off relay including contacts of said being normally out of holding engagement.

34. A line switch comprising sets of passive contacts, each set including line and test contacts, wipers for co-operation with each contact of said sets respectively, means for advancing said wipers to successively engage said sets of contacts, resilient means adapted for restoring said wipers, a pair of check pawls for controlling the restoration of said wipers, and a cut-off relay for controlling said pawls.

, 35. A line switch comprising sets of passivecontact's, each set including line and test contacts, wipers forco-operation with each pawls being normally out of holding engagement, and a single electromagnet for controllin said pawls.

36. line switch comprising passive contacts, a wiper for co-operation therewith, means for advancing said wiper to successively engage said contacts, means adapted for restoring said wiper, a pair of holding members adapted to control the restoration of said wiper, one of said members being normally in holding engagement and the other of said members being normally out of holding engagement, and a single electromagnet for controlling said members.

3 A line switch comprising passive contacts, a wiper for co-operation therewith, means for advancing said wiper to engage said contacts, means adapted for restoring said wiper, a pair of check pawls for controlling the restoration of said wiper, one of said pawls being normally in holding'e'ngagement and the other of said pawls being normally out of holding engagement, and a single electromagnet for controlling said pawls.

38. A line switch comprising passive contacts, a wiper for co-operatio'n therewith, a motor magnet for advancing said wiper to select one of said contacts, means adapted for restoring said wiper, a pair of check pawls for controlling the restoration of said wiper, and a cut-off relay for controllin both of said pawls.

39. n automatic switch comprising a mounting frame, a bank of contacts carried thereby, wipers for co-operation with said bank contacts, a shaft for said wipers suitably supported by said frame, a rotary armature, a ratchet and a co-operating pawl therefor carried by said armature, an electromagnet for operating said armature to ad Vance the wipers over said contact bank, restoring means for the wipers, a pair of pawls for holding the wipers in advanced position and a single electromagnet for operating said holding pawls to permit said restoring means to return said wlpers to normal.

40. An automatic switch comprising a mounting frame, a contact bank supported thereby, self-restoring wipers'for co-operation with said contact bank, a shaft for said wipers suitably supported by said frame, an armature, a ratchet, a co-operating pawl therefor carried by the armature, an electroma not supported by said frame and adapted or advancing said wipers, a pair of pawls for holding said wipers in an advanced position and for releasing the same from said advanced position, and a single electromagnet for controlling the said holding pawls.

41. An automatic telephone system in-' cluding a traveling" switch provlded with only three operating magnets, an adjusting magnet for said switch, a, magnet initially energized by current flowing over the talking circuit and thereafter operating in vibra tory relation with the adjusting magnet, and test means operating when sa d switch engages an idle contact to stop the vibration.

42. A non-numerical automatic switch provided with only three operating magnets, a line magnet and an adjusting magnet of said operating magnets being in vibratory relation, said line magnet initially energized by current over the talking circuit and thereafter controlled by the test means of the switch, said means serving to sto the vibration when the switch engages i le contacts.

43. A telephone line, a traveling switch therefor provided with only three operating magnets, one of said magnets having its winding connected to said line and operated by current-thereover, another of said magnets being an adjusting magnet for operating the switch, automatic means for placing said first magnet and said adjusting magnet in position to operate in vibratory relation, and a progressively movable test contact connected in circuit whereby said relation'terminates Y justing magnet, a relay initially energized by current flowing over a talking circuit and thereafter operating in Vibratory relation with the magnet, test means operating when said switch engages an idle'contactto stop the vibration, and a cut-off relay energized when said switch engages saididle contact.

45.-A telephone system including a subscribers telephone line, an automatic switch individual thereto provided with a line relay and an operating magnet, movable contacts for said switch, a circuit for said line relay including said subscribers line, and other circuits including said relay and magnet in vibratory relation during the selection of an idle contact by said active contacts, and a cut-off relay adapted to be energized when an idle contact is found to connect the subscribers line with some of said active contacts.

46. A telephone system including a subscribers telephone line, a switch therefor provided with a relay and an adjusting magnet, active contacts for said switch, a tive contacts engage idle contacts to connect circuit for said relay including a subscribers said subscribers line to said idle contacts. line, other circuits for said relay and said Signed by me at Chicago, in the county of 10 magnet whereby they may be included in a Cook and State of Illinois, this 27th dayof 5 vibratory circuit arrangement to advance July, 1918. the active contacts of said switch, and a relay. adapted to be energized when said ac- HARRY H. IDE. 

